This section introduces aspects that may help facilitate a better understanding of the inventions. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art.
Most mobile networks presently operate according to 2nd Generation (2G) or 3rd Generation (3G) standards to provide voice and data services. The trend for mobile networks is to evolve towards 4th Generation (4G) technologies. One project within the 3rd Generation Partnership Project (3GPP, 3GPP2) is the Long Term Evolution (LTE), which is a 4G technology intended to provide data rates of 100 mbps or more. The network architecture defined by this project is referred to as the Evolved Packet System (EPS). The EPS architecture comprehends e-UTRAN (evolved-UMTS Terrestrial Radio Access Network) on the radio access side and EPC (Evolved Packet Core) on the core side.
e-UTRAN is the air interface of the LTE network, and comprises a plurality of base stations that are referred to as Enhanced NodeBs (eNodeBs or eNBs). NodeB is a term used in UMTS to refer to a base station or cell site that interfaces a mobile device with a core network (similar to a base transceiver station (BTS) in a GSM network). A base station or network node includes antennas that communicate with mobile devices that are within a certain range. The coverage area surrounding the network node/base station is referred to as a “cell”. An eNodeB is comprised of multiple cells or sectors and is an enhanced base station that performs tasks similar to a nodeB in communicating with mobile devices.
LTE standards, such as 3GPP Technical Specification (TS) 36.331, allow an eNodeB to take itself out of service and suspend wireless service within its cell. This is typically referred to as “cell-barring”. There are a variety of situations where an eNodeB implements cell-barring. For example, an eNodeB may be scheduled for maintenance, a software update, a hardware update, etc. Also, an eNodeB may dynamically detect problems, such as connectivity between the eNodeB and a Mobility Management Entity (MME). When an eNodeB implements cell-barring, the eNodeB announces its unavailability in a System Information Message to mobile devices (or user equipment (UEs)) within its cells. The mobile devices that receive the System Information Message will exclude the barred cell as a candidate for cell selection.
However, edge UEs served by cells neighboring the barred eNB may continue to make handover (HO) attempts to the barred cell because these connected UEs may still see that the barred cell has a better signal (RSRP) than their current serving cell does. The HO requests are rejected, but the number of such attempts may exceed 40,000 per day. Clearly, wasted signaling and processing, such as in this cell-barring situation, is not desireable. Thus, new solutions and techniques that are able to address one or more of these issues would meet a need and advance wireless communications generally.
Specific embodiments of the present invention are disclosed below with reference to FIGS. 1-4. Both the description and the illustrations have been drafted with the intent to enhance understanding. For example, the dimensions of some of the figure elements may be exaggerated relative to other elements, and well-known elements that are beneficial or even necessary to a commercially successful implementation may not be depicted so that a less obstructed and a more clear presentation of embodiments may be achieved. In addition, although the logic flow diagrams above are described and shown with reference to specific steps performed in a specific order, some of these steps may be omitted or some of these steps may be combined, sub-divided, or reordered without departing from the scope of the claims. Thus, unless specifically indicated, the order and grouping of steps is not a limitation of other embodiments that may lie within the scope of the claims.
Simplicity and clarity in both illustration and description are sought to effectively enable a person of skill in the art to make, use, and best practice the present invention in view of what is already known in the art. One of skill in the art will appreciate that various modifications and changes may be made to the specific embodiments described below without departing from the spirit and scope of the present invention. Thus, the specification and drawings are to be regarded as illustrative and exemplary rather than restrictive or all-encompassing, and all such modifications to the specific embodiments described below are intended to be included within the scope of the present invention.